Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesic Agents

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Analgesics Medications that relieve pain without causing loss of consciousnessMedications that relieve pain without causing loss of consciousness PainkillersPainkillers

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Classification of Pain By Source Vascular pain Possibly originates from vascular or perivascular tissuesPossibly originates from vascular or perivascular tissues Neuropathic pain Results from injury to peripheral nerve fibers or damage to the CNSResults from injury to peripheral nerve fibers or damage to the CNS Superficial pain Originates from skin or mucous membranesOriginates from skin or mucous membranes

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Pain Transmission Tissue injury causes the release of: BradykininBradykinin HistamineHistamine PotassiumPotassium ProstaglandinsProstaglandins SerotoninSerotonin These substances stimulate nerve endings, starting the pain process.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Pain Transmission These pain fibers enter the spinal cord and travel up to the brain.These pain fibers enter the spinal cord and travel up to the brain. The point of spinal cord entry is the DORSAL HORN.The point of spinal cord entry is the DORSAL HORN. The DORSAL HORN is the location of the “GATE.”The DORSAL HORN is the location of the “GATE.”

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Pain Transmission This gate regulates the flow of sensory impulses to the brain.This gate regulates the flow of sensory impulses to the brain. Closing the gate stops the impulses.Closing the gate stops the impulses. If no impulses are transmitted to higher centers in the brain, there is NO pain perception.If no impulses are transmitted to higher centers in the brain, there is NO pain perception.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Pain Transmission Body has endogenous neurotransmittersBody has endogenous neurotransmitters –Enkephalins –Endorphins Produced by body to fight painProduced by body to fight pain Bind to opioid receptorsBind to opioid receptors Inhibit transmission of pain by closing gateInhibit transmission of pain by closing gate

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Pain Transmission Rubbing a painful area with massage or liniment stimulates large sensory fibers Result:Result: –GATE closed, recognition of pain REDUCED –Same pathway used by opiates

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics Pain relievers that contain opium, derived from the opium poppyPain relievers that contain opium, derived from the opium poppyor chemically related to opiumchemically related to opium Narcotics: very strong pain relievers

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics codeine sulfatecodeine sulfate meperidine HCl (Demerol)meperidine HCl (Demerol) methadone HCl (Dolophine)methadone HCl (Dolophine) morphine sulfatemorphine sulfate propoxyphene HClpropoxyphene HCl

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Mechanism of Action Bind to receptors on inhibitory fibers, stimulating themBind to receptors on inhibitory fibers, stimulating them Prevent stimulation of the GATEPrevent stimulation of the GATE Prevent pain impulse transmission to the brainPrevent pain impulse transmission to the brain

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Therapeutic Uses Main use: to alleviate moderate to severe pain Opioids are also used for:Opioids are also used for: –Cough center suppression –Treatment of constipation

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Side Effects EuphoriaEuphoria Nausea and vomitingNausea and vomiting Respiratory depressionRespiratory depression Urinary retentionUrinary retention Diaphoresis and flushingDiaphoresis and flushing Pupil constriction (miosis)Pupil constriction (miosis) ConstipationConstipation

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiate Antagonists naloxone (Narcan) naltrexone (Revia) Opiate antagonistsOpiate antagonists Bind to opiate receptors and prevent a responseBind to opiate receptors and prevent a response Used for complete or partial reversal of opioid-induced respiratory depression

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiates: Opioid Tolerance A common physiologic result of chronic opioid treatmentA common physiologic result of chronic opioid treatment Result:larger dose of opioids are required to maintain the same level of analgesiaResult:larger dose of opioids are required to maintain the same level of analgesia

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiates: Physical Dependence The physiologic adaptation of the body to the presence of an opioidThe physiologic adaptation of the body to the presence of an opioid

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiates: Psychological Dependence (addiction) A pattern of compulsive drug use characterized by a continued craving for an opioid and the need to use the opioid for effects other than pain reliefA pattern of compulsive drug use characterized by a continued craving for an opioid and the need to use the opioid for effects other than pain relief

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiates Opioid tolerance and physical dependence are expected with long-term opioid treatment and should not be confused with psychological dependence (addiction).Opioid tolerance and physical dependence are expected with long-term opioid treatment and should not be confused with psychological dependence (addiction).

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiates Misunderstanding of these terms leads to ineffective pain management and contributes to the problem of undertreatment.Misunderstanding of these terms leads to ineffective pain management and contributes to the problem of undertreatment.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiates Physical dependence on opioids is seen when the opioid is abruptly discontinued or when an opioid antagonist is administered.Physical dependence on opioids is seen when the opioid is abruptly discontinued or when an opioid antagonist is administered. –Narcotic withdrawal –Opioid abstinence syndrome

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opiates Narcotic Withdrawal Opioid Abstinence Syndrome Manifested as:Manifested as: –anxiety, irritability, chills and hot flashes, joint pain, lacrimation, rhinorrhea, diaphoresis, nausea, vomiting, abdominal cramps, diarrhea

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Before beginning therapy, perform a thorough history regarding allergies, use of other medications,health history, and medical history.Before beginning therapy, perform a thorough history regarding allergies, use of other medications,health history, and medical history. Obtain baseline vital signs and I & O.Obtain baseline vital signs and I & O. Assess for potential contraindications and drug interactions.Assess for potential contraindications and drug interactions.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Perform a thorough pain assessment, including nature and type of pain, precipitating and relieving factors, remedies, and other pain treatments.Perform a thorough pain assessment, including nature and type of pain, precipitating and relieving factors, remedies, and other pain treatments. –Assessment of pain is now being considered a “fifth vital sign.”

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Be sure to medicate patients before the pain becomes severe as to provide adequate analgesia and pain control.Be sure to medicate patients before the pain becomes severe as to provide adequate analgesia and pain control. Pain management includes pharmacologic and nonpharmacologic approaches. Be sure to include other interventions as indicated.Pain management includes pharmacologic and nonpharmacologic approaches. Be sure to include other interventions as indicated.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Oral forms should be taken with food to minimize gastric upset.Oral forms should be taken with food to minimize gastric upset. Ensure safety measures, such as keeping side rails up, to prevent injury.Ensure safety measures, such as keeping side rails up, to prevent injury. Withhold dose and contact physician if there is a decline in the patient’s condition or if VS are abnormal—especially if respiratory rate is below 12 breaths/minute.Withhold dose and contact physician if there is a decline in the patient’s condition or if VS are abnormal—especially if respiratory rate is below 12 breaths/minute.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Follow proper administration guidelines for IM injections, including site rotation.Follow proper administration guidelines for IM injections, including site rotation. Follow proper guidelines for IV administration, including dilution, rate of administration, and so forth.Follow proper guidelines for IV administration, including dilution, rate of administration, and so forth. CHECK DOSAGES CAREFULLY

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Constipation is a common side effect and may be prevented with adequate fluid and fiber intake.Constipation is a common side effect and may be prevented with adequate fluid and fiber intake. Instruct patients to follow directions for administration carefully, and to keep a record of their pain experience and response to treatments.Instruct patients to follow directions for administration carefully, and to keep a record of their pain experience and response to treatments. Patients should be instructed to change positions slowly to prevent possible orthostatic hypotension.Patients should be instructed to change positions slowly to prevent possible orthostatic hypotension.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Patients should not take other medications or OTC preparations without checking with their physician.Patients should not take other medications or OTC preparations without checking with their physician. Instruct patients to notify physician for signs of allergic reaction or adverse effects.Instruct patients to notify physician for signs of allergic reaction or adverse effects.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Monitor for side effects: Should VS change, patient’s condition decline, or pain continue, contact physician immediately.Should VS change, patient’s condition decline, or pain continue, contact physician immediately. Respiratory depression may be manifested by respiratory rate of less than 12/min, dyspnea, diminished breath sounds, or shallow breathing.Respiratory depression may be manifested by respiratory rate of less than 12/min, dyspnea, diminished breath sounds, or shallow breathing.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Opioid Analgesics: Nursing Implications Monitor for therapeutic effects: Decreased complaints of painDecreased complaints of pain Increased periods of comfortIncreased periods of comfort With improved activities of daily living, appetite, and sense of well-beingWith improved activities of daily living, appetite, and sense of well-being

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Central Nervous System Depressants

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants Sedatives Drugs that have an inhibitory effect on the CNS to the degree that they reduce:Drugs that have an inhibitory effect on the CNS to the degree that they reduce: –Nervousness –Excitability –Irritability –without causing sleep

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants Hypnotics Calm or soothe the CNS to the point that they cause sleepCalm or soothe the CNS to the point that they cause sleep

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants Sedative-Hypnotics—dose dependent: At low doses, calm or soothe the CNS without inducing sleepAt low doses, calm or soothe the CNS without inducing sleep At high doses, calm or soothe the CNS to the point of causing sleepAt high doses, calm or soothe the CNS to the point of causing sleep

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Sedative-Hypnotics: Barbiturates Barbiturates have a very narrow therapeutic index. Therapeutic Index Dosage range within which the drug is effective but above which is rapidly toxic.Dosage range within which the drug is effective but above which is rapidly toxic.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Sedative-Hypnotics: Barbiturates Mechanism of Action Site of action:Site of action: –Brain stem (reticular formation) –Cerebral cortex By inhibiting GABA, nerve impulses traveling in the cerebral cortex are also inhibited.By inhibiting GABA, nerve impulses traveling in the cerebral cortex are also inhibited.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Sedative-Hypnotics: Barbiturates Drug Effects Low doses:Sedative effectsLow doses:Sedative effects High doses:Hypnotic effects (also lowers respiratory rate)High doses:Hypnotic effects (also lowers respiratory rate) Notorious enzyme inducers

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Sedative-Hypnotics: Barbiturates Therapeutic Uses HypnoticsHypnotics SedativesSedatives AnticonvulsantsAnticonvulsants Surgical proceduresSurgical procedures

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Sedative-Hypnotics: Barbiturates Side Effects Body SystemEffects CNSDrowsiness, lethargy, vertigo mental depression, coma RespiratoryRespiratory depression, apnea, bronchospasms, cough

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Sedative-Hypnotics: Barbiturates Side Effects Body SystemEffects GINausea, vomiting, diarrhea OtherAgranulocytosis, vasodilation, hypotension, Stevens-Johnson syndrome

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. Sedative-Hypnotics: Barbiturates Toxicology Overdose frequently leads to respiratory depression, and subsequently, respiratory arrest.Overdose frequently leads to respiratory depression, and subsequently, respiratory arrest. Can be therapeutic:Can be therapeutic: –Anesthesia induction –Uncontrollable seizures: “phenobarbital coma”

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants: Benzodiazepines Mechanism of Action Depress CNS activityDepress CNS activity Affect hypothalamic, thalamic, and limbic systems of the brainAffect hypothalamic, thalamic, and limbic systems of the brain Benzodiazepine receptorsBenzodiazepine receptors

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants: Benzodiazepines Drug Effects Calming effect on the CNSCalming effect on the CNS Useful in controlling agitation and anxietyUseful in controlling agitation and anxiety

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants: Nursing Implications Before beginning therapy, perform a thorough history regarding allergies, use of other medications,health history, and medical history.Before beginning therapy, perform a thorough history regarding allergies, use of other medications,health history, and medical history. Obtain baseline vital signs and I & O, including supine and erect BPs.Obtain baseline vital signs and I & O, including supine and erect BPs. Assess for potential disorders or conditions that may be contraindications, and for potential drug interactions.Assess for potential disorders or conditions that may be contraindications, and for potential drug interactions.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants: Nursing Implications Give 15 to 30 minutes before bedtime for maximum effectiveness in inducing sleep.Give 15 to 30 minutes before bedtime for maximum effectiveness in inducing sleep. Most benzodiazepines (except flurazepam) cause REM rebound and a tired feeling the next day; use with caution in the elderly.Most benzodiazepines (except flurazepam) cause REM rebound and a tired feeling the next day; use with caution in the elderly. Patients should be instructed to avoid alcohol and other CNS depressants.Patients should be instructed to avoid alcohol and other CNS depressants.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants: Nursing Implications Check with physician before taking any other medications, including OTC medications.Check with physician before taking any other medications, including OTC medications. It may take 2 to 3 weeks to notice improved sleep when taking barbiturates.It may take 2 to 3 weeks to notice improved sleep when taking barbiturates. Abruptly stopping these medications, especially barbiturates, may cause rebound insomnia.Abruptly stopping these medications, especially barbiturates, may cause rebound insomnia.

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants: Nursing Implications Safety is importantSafety is important –Keep side rails up –Do not permit smoking –Assist patient with ambulation (especially the elderly) –Keep call light within reach Monitor for side effectsMonitor for side effects

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved. CNS Depressants: Nursing Implications Monitor for therapeutic effectsMonitor for therapeutic effects –Increased ability to sleep at night –Fewer awakenings –Shorter sleep induction time –Few side effects, such as hangover effects –Improved sense of well-being because of improved sleep